During the production of fibers for paper making, wood or another fiber source is ground into chips and/or mechanically treated such that the chips may be broken down further and refined into individual fibers.
Disc refiners are used with high density stock containing forty to sixty percent fiber by weight to break down clumps of fibers into individual fibers. Disc refiners are also used with low density, low consistency pulp of two to five percent fiber dry weight to increase the freeness or bonding capability of the individual fibers.
The refiner disc consists of a disc-shaped steel or steel-alloy casting which has a multiplicity of more-or-more less radially extending bars cast on the surface thereof. One disc is mounted on a rotor for rotation and another disc is held opposed to the first refiner disc, either by rigid mounting or by mounting on an opposing rotating rotor. The refiner discs, as they move past each other, separate and refine the wood pulp as it passes between the opposed discs.
A refiner for high density stock employs an auger which is axially mounted with respect to the rotor on which the refining disks are mounted. Positioned adjacent to the end of the auger is a flinger nut which feeds the stock into a breaker bar section which in turn feeds the stock to the refiner disks where wood chips and clumps of fiber are broken down into individual fibers. Conventional flinger nuts employ radially extending vanes which become worn, necessitating expensive replacement of the flinger nut.
In the manufacture of paper, the cost of the stock or wood fibers used to manufacture the paper is the single largest component in the cost of the paper made. The paper fibers or stock is manufactured from wood chips which are in many aspects an industrial commodity whose price is governed by the market and not easily controlled. Thus, in improving the cost and efficiency of the papermaking process, it is important to focus on reducing the cost of processing the wood chips to produce the stock or furnish from which the paper is made. High density refiners which are used principally with mechanical or semi-chemical pulps are subjected to an intense wear environment. The wood chips which are fed to the refiner can contain sand and grit, which in the environment of the high density stock can produce relatively rapid ware.
What is needed is a flinger nut which can be efficiently maintained for improved wear life.